This is rare, but it happens to heavy users. The only solution is a full environment reset:
To protect your main Instagram account from potential shadowbans or permanent blocks, many users recommend creating a secondary account solely for use with 4K Stogram. 4k stogram api error
Completely log out of 4K Stogram, restart the application, and log back in. If you receive a "Challenge Required" error, log in via a mobile browser first to verify your identity and then return to the app. This is rare, but it happens to heavy users